The Febco® freeze protection Model 765 is a popular backflow prevention device. An above ground supply water extension provides a vertical path to atmosphere when the supply water is off. A first spring loaded check valve is normally spring loaded closed when the supply water is off or loses pressure while on. Above the first check valve is a plastic bonnet and poppet release valve to atmosphere. If this breaks during a freeze, it can be readily replaced. This bonnet and poppet is spring loaded open to atmosphere. The supply water pressure closes this bonnet and poppet during the sprinkling operation.
The FEBCO Series 765 Pressure Vacuum Breakers are used to protect against health hazard and non-health hazard backsiphonage conditions in industrial plants, cooling towers laboratories, laundries, swimming pools and lawn sprinkler systems.
The FEBCO 765 PVB is designed to be installed to provide protection against backsiphonage of toxic or non-toxic liquids. It consists of a spring loaded check valve which closes tightly when the pressure in the assembly drops below 1 psi or when zero flow occurs, plus, an air relief valve that opens to break a siphon when the pressure in the assembly drops to 1 psi.
Pressure Vacuum Breaker assemblies shall be installed to withstand pressure for long periods and to prevent backflow of contaminated water into the potable water system in backsiphonage conditions. The Pressure Vacuum Breaker assembly shall consist of single spring loaded check valve which closes tightly when water flow through the assembly drops to zero, and a single air relief valve that opens to break the siphon when pressure drops to 1 psi. The assembly shall include two resilient seated shut-offs and two resilient seated test cocks, considered integral to the assembly. Assemblies must be factory backflow tested. The check valve and air inlet valve must be constructed to allow in-line servicing of the assembly. The valve body shall be constructed of bronze. The check, poppet and bonnet assembly shall be constructed of engineered plastic to protect the valve body from freeze damage.
Pressure Vacuum Breaker assemblies shall be installed a minimum of 12″ (300 mm) above the highest downstream outlet, and the highest point in the downstream piping. The assembly shall be rated to 150 psi working pressure and water temperature from 32° to 140° F. The assembly shall meet the specifications of the USC-FCCC & HR Manual.
FIG. 1 shows the prior art all Febco® installation 1000. Supply water line 1 has a manual shut off valve 2. An inlet drain valve 3 is used for winterization draining. A manual shut off valve 4 allows repair of a Febco® Backflow casing 5. A cap 6 vents to atmosphere. Inside the casing 5 is a disposable bonnet and poppet 2000 shown in FIG. 2. A shut off valve 7 provides water to sprinklers 8 past an outlet drain valve 10. The house exterior wall is designated 9.
If the bonnet and poppet 2000 gets frozen and breaks, then when the sprinklers are turned on, a flood will occur as shown next to the house 9. This can ruin a basement. What is needed in the art is a much stronger bonnet and poppet produced at about the same cost in order to offer the homeowner further protection from catastrophic flooding especially during fall and spring waterings when the house may be unoccupied during a quick freeze before the sprinklers have been winterized.
The present invention has over 50% improvement of the breaking strength as the prior art using about the same number of parts at about an equivalent cost to produce.